Hi guys. I don't think my car comes with pre wired factory alarm. At first I'm not really bother with it but becomes more aware about the safety soon after that. Does anyone know what I would need to retrofit the factory alarm? How much does it cost? Is any of you ever try this thing before? FYI, mine is 2011 E82.

I plan to do it in next few months but have to do my homework, which is research, right now. Please help me out guys. Really appreciate your thoughts and opinions. Thanks!